Muffler having two parallel bores with slotted baffles



Nov. 18, 1969 E. A. MATTIE I 3,478,842

MUFFLER HAVING TWO PARALLEL BORES WITH SLOTTED BAFFLES Filed Dec. 29, 1967 3 Sheets-Sheet 1 o 0 0:: S n O o di m Cn q o INVENTOR.

EUGENE A. MATTIE BY mm Clumqwm ATTORNEY Nov. 18, 1969 E. A. MATTIE 3,478,842

MUFFLER HAVING TWO PARALLEL BORES WITH SLOTTED BAFF'LES Filed Dec. 29, 1967 3 Sheets-Sheet 2 FIG. 4

INVENTOR.

BY EUGENE A. MATTIE ATTORNEYS E. A. MATTIE Nov. 18, 1969 MUFFLER HAVING TWO PARALLEL BORES WITH SLOTTED BAFFLES INVENTOR. EUGENE A. MATTIE BY wmmumwwm ATTORNEYS United States Patent 3,478,842 MUFFLER HAVING TWO PARALLEL BORES WITH SLOTTED BAFFLES Eugene A. Mattie, Metacomett Road, Scituate, Mass. 02060 Filed Dec. 29, 1967, Ser. No. 694,594 Int. Cl. F01n l/08 U.S. Cl. 18156 6 Claims ABSTRACT OF THE DISCLOSURE A muffier is made using precise specific dimensions varying for different sizes. The muffier is made in two parts each of which can be die-cast. When assembled the muffler consists of two parallel tubes each having eleven baffles therein, each bafiie being slightly inclined and having a plurality of slots therethrough aligned with corresponding slots in the other bafiles in the tube, the inlet and outlet of the muffler each having a cross-sectional area no greater than the combined areas of the apertures in the initial baffies in the two tubes.

This invention relates to mufllers for internal combustion motors designed so that the compression waves in the exhaust gases cancel one another out, resulting in a smooth discharge flow of gases which is virtually silent. As hereinafter described, the mufiler consists of two parts each of which can be die-cast for economic production and which are designed to be secured together to form an inlet orifice expanding into a pair of parallel bores which merge in a common chamber tapering to a discharge outlet orifice. To be elfective, the muffler must be formed carefully in accordance with the dimensions given for each specified size.

For a more complete understanding of the invention, reference may be had to the following description thereof and to the drawings, of which:

FIGURE 1 is a perspective external view of a muffier embodying the invention;

FIGURE 2 is a plan view of one of the two parts which are joined to make a complete muffler;

FIGURE 3 is a transverse sectional view, on a larger scale, of the muffler shown in FIGURE 1;

FIGURE 4 is a fragmentary section on the line 4-4 of FIGURE 3; and

FIGURE 5 shows a table of dimensions of mufilers of various sizes embodying the invention.

As indicated in FIGURE 2, the mufiler has an inlet orifice which opens into a chamber 12. This chamber branches into two parallel bores 13, 14. Each bore has eleven bafiles 16 each of which starts from one side of a bore in a substantially radial direction and curves away from the inlet until it meets a segmental element 18 at the other side of the bore in a substantially axial direction. Each baflie 16 has a number of elongated slots 20, 22, 24, 26 therethrough, these slots being of equal width and extending through the bafile Wall in an axial direction. As the several baffles are identical, the corresponding slots 3,478,842 Patented Nov. 18, 1969 "ice in the baffles are axially aligned. Each slot has parallel side edges and semicircular ends. The combined areas of the slots through a wall in each of the bores is preferably equal to but not less than the cross-sectional area of the inlet 10.

The discharge ends of the bores 13, 14 merge in a discharge chamber 34 which terminates in a discharge orifice 36.

As indicated in FIGURE 4, the baffle walls 16 are inclined a few degrees with reference to planes perpendicular to the axes of the bores. Hence the parts 30 and 32 of the muffler are not identical but are nearly so, owing to the slant of the baffle walls. These parts are designed to be capable of being manufactured by die-casting.

The size of a mufiler made for an engine will depend on the horse-power of the engine. By making a mufiier as illustrated on the drawings and carefully following the dimensions given in the table shown in FIGURE 5, an

effective mufiler will be had in which the compression Waves in the exhaust gases will cancel one another out and a quiet outflow from the discharge outlet Will result.

I claim:

1. A muffler for use with internal combustion engines, comprising a casing having an inlet orifice and a discharge orifice and forming two parallel bores communicating with said orifices, each said bore having a plurality of bafiles therein, each said bafile having a plurality of slots therethrough, the slots in each baffie being axially aligned with the corresponding slots in the other baffies in the same bore.

2. A mufller as claimed in claim 1, each said baffle curving from an approximately radial direction at one side of its bore to an approximately axial direction at the other side.

3. A mufller as claimed in 1, each said slot being elongated with parallel side edges and semicircular ends.

4. A mufiler as claimed in claim 1, each said bore having eleven bafl'les therein.

5. A muffler as claimed in claim 2, said bafiles being inclined slightly with reference to planes perpendicular to the axes of said bores.

6. A mufiier as claimed in claim 5, each said bore having eleven baffles therein.

References Cited UNITED STATES PATENTS 1,758,654 5/1930 Dormeyer. 2,172,147 9/1939 Smith 18169 XR 2,561,557 7/1951 Biddlecombe. 3,135,350 6/1964 Mattie 18161 XR FOREIGN PATENTS 292,613 6/ 1929 Great Britain. 116,512 2/1930 Austria.

ROBERT S. WARD, In, Primary Examiner U.S. Cl. X.R. 18161, 

